Two piece armored optical cables

ABSTRACT

An armored cable includes a core and an armor surrounding the core. The armor includes at least one armor access feature formed in the armor to weaken the armor at the access feature. A jacket surrounds the armor and the jacket includes a primary portion of a first extruded polymeric material and at least one discontinuity of a second extruded polymeric material in the primary portion, the discontinuity extending along a length of the cable, and the first material being different from the second material, wherein the bond between the discontinuity and the primary portion allows the jacket to be separated at the discontinuity to provide access to the core, and the at least one armor access feature and the at least one discontinuity are arranged proximate to each other to allow access to the core.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/426,641 filed May 30, 2019, which is a continuation of InternationalApplication No. PCT/US17/63569, filed on Nov. 29, 2017, which claims thebenefit of priority to U.S. Application No. 62/428,526, filed on Nov.30, 2016, both applications being incorporated herein by reference.

BACKGROUND

An armored fiber optic cable is disclosed, specifically a fiber opticcable having access features for accessing a core of the fiber opticcable, and an armor layer having armor halves to further enhance coreaccess features of the cable.

BRIEF DESCRIPTION OF THE DRAWINGS

According to common practice, the various features of the drawingsdiscussed below are not necessarily drawn to scale. Dimensions ofvarious elements in the drawings may be expanded or reduced to moreclearly illustrate embodiments of the invention.

FIG. 1 is a cross-sectional view of a fiber optic cable according to afirst embodiment.

FIG. 2 is a perspective view of the cable illustrated in FIG. 1.

FIG. 3 is an isolated partial view of an armor piece in accordance withaspects of the present disclosure.

FIG. 4 is a cutaway sectional view of a portion of an armor piece withchord-shear shapes in accordance with aspects of the present disclosure.

FIG. 5 is an illustration of a punched teardrop feature of an armorpiece in accordance with aspects of the present disclosure.

FIG. 6 is an illustration of a punched curve feature of an armor piecein accordance with aspects of the present disclosure.

FIGS. 7A and 7B illustrate a metal armor piece with shear cuts havingcurved edges and formed as tabs in accordance with aspects of thepresent disclosure.

FIG. 8 illustrates a metal armor piece with shear cuts stretched to formopen sections in accordance with aspects of the present disclosure.

FIG. 9 illustrates various configurations for armor halves in accordancewith aspects of the present disclosure.

FIG. 10 illustrates various configurations of butt splices for armorhalves in accordance with aspects of the present disclosure.

FIG. 11 illustrates various configurations for armor overlaps withrespect to strength members and fast access features, in accordance withaspects of the present disclosure.

DETAILED DESCRIPTION

Reference is now made in detail to the present preferred embodiments ofthe disclosure, examples of which are illustrated in the accompanyingdrawings. Whenever possible, identical or similar reference numerals areused throughout the drawings to refer to identical or similar parts.

Referring generally to the figures, various embodiments of an opticalcommunication cable (e.g., a fiber optic cable, an optical fiber cable,etc.) are shown. In general, the cable embodiments disclosed hereininclude one or more optical transmission elements wrapped in aprotective, reinforcement or armor material (e.g., a corrugated metalsheet of material). A cable body or jacket formed from a polymermaterial (e.g., a medium density polyethylene material) surrounds thearmored group of optical fibers. Generally, the cable jacket providesphysical support and protection to the optical fibers within the cableand the armor material provides additional reinforcement to the opticalfibers within the cable body.

In various embodiments discussed herein, the reinforcement layer isformed from at least two separate pieces or sheets of material that areeach wrapped a portion of the distance around the optical fibers.Because the reinforcement layer is formed from two pieces of material,the opposing lateral edges of each sheet of reinforcement material maybe overlapped, coupled to or bonded together to form a reinforcementlayer surrounding the optical fibers. In various embodiments, inaddition to holding the two segments of the reinforcement layer togetheraround the optical fibers, the coupling between the two segments of thereinforcement layer may also provide for additional circumferentialand/or axial rigidity to the cable. In addition, in contrast tosingle-piece wrapped armor layers typical in fiber optic cables, theindividual sections of the multi-piece reinforcement layer discussedherein do not form a complete loop, allowing both inner and outertooling to be used to more precisely shape the segments of thereinforcement layer to fit snuggly around the optical transmissionelements of the cable..

In addition to the formation and strength functions discussed above, themulti-piece reinforcement layer discussed herein works in conjunctionwith easy access features to provide easy access to optical fiberswithin the cable, in various embodiments. In such embodiments, the cablejacket may include two or more easy access features (e.g., coextrudeddiscontinuities within the material of the cable jacket) that providefor splitting of the jacket by the user. In various embodiments, theeasy access features may be located adjacent to the lateral edges of thesegments of the reinforcement layer and the reinforcement layers may bebonded to the cable jacket. In such embodiments, when the cable jacketis opened by splitting along the easy access features, the segments ofreinforcement layer may remain bonded to the cable jacket and theseparate segments of the reinforcement layer allowed to separate fromeach other. This arrangement allows for easy access to the opticalfibers within the cable with a single opening action.

Referring to FIGS. 1 and 2, an optical communication cable, shown ascable 10, is shown according to an exemplary embodiment. Cable 10includes a cable body, shown as cable jacket 12, having an inner surface14 that defines an inner passage or cavity, shown as central bore 16. Aswill be generally understood, inner surface 14 of jacket 12 defines aninternal area or region within which the various cable componentsdiscussed below are located. Generally, cable 10 provides structure andprotection to optical fibers 18 during and after installation (e.g.,protection during handling, protection from elements, protection fromvermin, etc.).

In the embodiment shown in FIG. 1, cable 10 includes a plurality of coreelements located within central bore 16. A first type of core element isan optical transmission core element, and in this embodiment, theoptical transmission core elements include optical fibers 18, which maybe, for example, 200 μm low loss optical fibers stacked in a 6 fiberribbon subunit base structure which achieves better fiber density for agiven diameter compared to conventional ribbons. In accordance withaspects of the present disclosure, the 6 fiber subunit base structuremay be used in 6, 12, 18, 24, 30 and 36 fiber ribbon widths. As shown inFIGS. 1 and 2, core elements may include a buffer tube 20 and a film ormembrane, shown as binding film 28, located around buffer tube 20. Thinfilm 28 may be an extruded thin film that cools to provide an inwardlydirected force on to buffer tube 20.

In various embodiments, film 28 is formed from a first material andjacket 12 is formed from a second material. In various embodiments, thefirst material is different from the second material. In some suchembodiments, the material type of the first material is different fromthe material type of the second material. In various embodiments, film28 may be formed from a variety of extruded polymer materials. Invarious embodiments, film 28 may be formed from low-density polyethylene(LDPE), polyester or polypropylene. In one embodiment, film 28 is formedfrom a linear LDPE. In one embodiment, film 28 is formed from an LDPEmaterial having a modulus of elasticity between 600 MPa and 1000 MPa,and more specifically about 800 MPa (e.g., 800 MPa plus or minus 5percent). In one embodiment, film 28 is formed from a polyester materialhaving a modulus of elasticity between 2000 MPa and 2800 MPa, and morespecifically about 2400 MPa (e.g., 2400 MPa plus or minus 5 percent). Invarious embodiments, the material of film 28 may include a coloringmaterial. In one such embodiment, film 28 may be colored the same asjacket 12. In one such embodiment, the material of film 28 may be apolymer material (e.g., LDPE, PP) including carbon black coloringmaterial, and the different material of jacket 12 may be a differentpolymer material (e.g., medium density polyethylene) that also includescarbon black coloring material. In addition, film 28 may include UVstabilizing compounds and may include weakened areas (e.g., lowerthickness areas) that facilitate tearing and opening along with othercomponents of cable 10 discussed herein.

As noted above, the material of film 28 is different from the materialof jacket 12. In some such embodiments, film 28 is formed from a firstmaterial that is extruded at an earlier time or earlier stage in cableproduction than jacket 12. In such embodiments, film 28 is formed priorto formation of jacket 12. In some such embodiments, a first extrusionprocess forms film 28 at an earlier time in cable production, and asecond extrusion process forms jacket 12 at a later time in cableproduction. In some such embodiments, the first material of film 28 andthe second material of jacket 12 are the same type of material (e.g.,both are MDPE, PP, etc.) that are associated with cable 10 at differenttime points during the production of cable 10. In other embodiments, thefirst material of film 28 and the second material of jacket 12 are thedifferent types of material (e.g., film 28 is an LDPE and jacket 12 isMDPE) and are also associated with cable 10 at different time pointsduring production of cable 10.

In various embodiments, a layer of powder, such as water absorbingpowder or particles, such as super absorbent polymer (SAP), or a waterswellable gel or liquid, is located within bore 16. In such embodiments,the inner surface of film 28 may include the water absorbent particlesor other material that directly contacts the outer surface of buffertube 20.

As shown, cable 10 includes a reinforcement sheet or layer, shown asarmor layer 30, that is located outside of film 28 in the exemplaryarrangement of FIG. 1. Armor layer 30 is wrapped around the interiorelements (including optical fibers 18) of cable 10 such that armor layer30 surrounds optical fibers 18. Armor layer 30 generally provides anadditional layer of protection to fibers 18 within cable 10, and mayprovide resistance against damage (e.g., damage caused by contact orcompression during installation, damage from the elements, damage fromrodents, etc.).

In an exemplary embodiment, armor layer 30 is located outside of binderfilm 28. In various embodiments, armor layer 30 is formed from acorrugated sheet of metal material having an alternating series ofridges and troughs. In one embodiment, the corrugated metal is steel. Inother embodiments, other non-metallic strengthening materials may beused. For example, armor layer 30 may be formed from fiberglass yarns(e.g., coated fiberglass yarns, rovings, etc.). In some embodiments,armor layer 30 may be formed from plastic materials having a modulus ofelasticity over 2 GPa, and more specifically over 2.7 GPa. Such plasticarmor layers may be used to resist animal gnawing and may includeanimal/pest repellant materials (e.g., a bitter material, a peppermaterial, synthetic tiger urine, etc.). In one embodiment, cable 10could include a layer of nylon 12 acting to resist termites.

As shown in FIGS. 1 and 2, armor layer 30 includes a first segment 32and a second segment 34. First segment 32 has a first lateral edge 36and a second lateral edge 38, and second segment 34 has first lateraledge 40 and a second lateral edge 42. In the embodiment shown, lateraledges 36, 38, 40 and 42 are substantially parallel to the longitudinalaxis of cable 10. In various embodiments discussed herein, lateral edge36 of first segment 32 is positioned adjacent to lateral edge 40 ofsecond segment 34, and lateral edge 38 of first segment 32 is positionedadjacent to lateral edge 42 of second segment 34 such that combinedfirst segment 32 and second segment 34 form a reinforcement layer thatsurrounds the plurality of core elements. While the embodimentsdiscussed herein relate primarily to cables including two-piecereinforcement layers, in other embodiments, armor layer 30 can bemulti-piece armor layers that include three, four, five or more segmentswith peripheral edges and overlaps as discussed herein.

In the embodiment of FIGS. 1 and 2, first segment 32 and second segment34 of armor layer 30 are wrapped around the core elements such thatlateral edge 36 of first segment 32 passes over or overlaps lateral edge40 of second segment 34 creating a first overlap portion 44 and thatlateral edge 38 of first segment 32 passes over or overlaps lateral edge42 of second segment 34 creating a second overlap portion 46. Overlapportion 46 may be spaced more or less than 180 degrees from overlapportion 44. The overlap portions may overlap 2.5-3.0 mm, or morepreferably the overlap dimension may be between 0.5-1.5 mm.

In various embodiments, the sections of armor segments 32 and 34 withinoverlap portions 44 and 46 may be coupled together to help maintainmulti-piece armor layer 30 in the wrapped arrangement shown in FIGS. 1and 2. In one embodiment, a bonding agent or adhesive may be locatedbetween opposing surfaces within overlap portions 44 and 46 to bindarmor segments 32 and 34 together. In other embodiments, one or moremechanical coupling arrangements, such as welding, either continuous orintermittently, may be used to couple armor segment 32 to armor segment34.

Two overlaps instead of one as is typical in conventional armored cablesmay significantly reduce one of the causes of jacket zippering. During atwist action on a single armor cable, the outer overlap travels in oneaxial direction, and the inner overlap or ‘underlap’ travels in theother axial direction, causing an elongation of the bonded polyethylenejacket that is beyond the elongation limit. For two overlaps, the totalincluded axial distance will be at least half. Moreover, with precisionplacement of overlaps, aspects of the present disclosure includeproviding for a bond-free zone at the jacket/overlap edge/underlapback-edge intersection. With precision angular placement in theextrusion crosshead, a glue bead or other suitable material may becoextruded for special jacket slip properties at the overlap edge areas.

Two-piece armor may offer an advantage in cycle flex. For example, theneutral axis of each half, during cable bending, may now be radiallyaway from the center of the cable. This would facilitate a smaller innerradius to outer radius (r/R) strain in the armor, allowing for nocorrugations in the armor layer 30 for larger diameter cables. Todaywith conventional one-overlap armor, up to a 5 mm core the armor doesnot have to be corrugated, and the cable will still pass GR-20 cycleflex (no armor cracks after 25 cycles at prescribed bend radiusmandrel). With two-piece armor, the core diameter may be up to 8, or upto 10 mm or larger before corrugations are required. Eliminatingcorrugations allows for a thinner armor layer (0.17 mm flat instead of0.70 mm corrugated thickness). This facilitates smaller diameter, lowerweight armored cables, and significant cost reduction in armor andjacket material (e.g., polyethylene) usage and cost. Corrugated armormay be 106% of the cable length, while un-corrugated armor uses lesssteel per cable length, or 100% of cable length.

The armor segments 32 and 34 may be formed with steel rollers so thatthe finished armor form fits with nearly complete circumferentialcontact with the core or tube. The extruded and cooling jacket in thewater trough will further radially compress the two armor segments ontothe core elements or tube 20. The armor segments 32 and 34 thus applyradial pressure to buffer tube 20 and will facilitate effective couplingwhich will keep the tube 20 from shrinking back in the jacket 12 whencables are lashed aerially, after seasonal temperature cycling.

In conventional armored cables, the armor inside diameter is difficultto form fit tight to the core elements. The tube to armor clearance orTAC is variable and changes across fiber count range, across jacketlines, and between setups. The two piece armor enables the tight formfit, thus enabling the cable to act more like a composite structureduring crush, bend, twist, impact, etc. This tight construction enablesthinner tube and jacket walls while maintaining the same relativeoverall cable strength.

Cable jacket 12 may include a plurality of embedded elongate members,shown as access features 50 and 52. In general, access features 50 and52 are elongate members or structures embedded within the material ofcable jacket 12. In various embodiments, access features 50 and 52 arecontiguous members that extend the length of cable jacket 12 between thefirst and second ends of the cable.

In general, cable jacket 12 is made from a first material, and accessfeatures 50 and 52 are made from a second material that is differentfrom the first material. The difference in materials provides adiscontinuity or weakness within cable jacket 12 at the location ofaccess features 50 and 52. These discontinuities provide an access pointthat allows a user of cable 10 to split cable jacket 12 when access tooptical fibers 18 is desired. In various embodiments, access features 50and 52 may be formed from a material (e.g., a polypropylene/polyethyleneblend) with low bonding relative to the material of cable jacket 12(e.g., a medium density polyethylene) that allows for jacket splittingby the user. In various embodiments, access features 50 and 52 may beformed (e.g., coextruded) as described below. In other embodiments,access features 50 and 52 are non-extruded elements, such as rip cords,that are embedded in the material of cable jacket 12.

In the exemplary embodiment, the access features 50, 52 are bonded tothe main portion of the jacket when the jacket 12 is extruded. The mainportion and the access features 50, 52 can be formed from extrudablepolymers, so that as the extrudate used to form the main portion of thejacket 12 and the access features 50, 52 cools and solidifies, theextrudates become bonded at an interface of the access features 50, 52.When the access features 50, 52 are formed while extruding in the samestep as the main portion of the jacket 12, the bond between accessfeatures 50, 52 and the remainder of the jacket 12 can be generallydescribed as enabled by polymer chain entanglement as the jacket 12solidifies. The jacket 12 accordingly comprises a cohesive compositestructure. The interfaces may be a transition region between thematerials of the main portion of the jacket 12 and the access features50, 52.

The access features 50, 52 can be relatively narrow strips in the jacket12, and may occupy relatively small portions of the jacketcross-sectional area AJ. In FIGS. 1 and 2, two access features 50, 52are formed in the jacket 12 to facilitate opening of the jacket as shownin FIG. 2. However, the number, spacing, shape, composition and otheraspects of the access features 50, 52 can be varied. For example, asingle access feature in the jacket 12 may be sufficient to allow thecable jacket 12 to be opened away from the core. The access features inFIG. 1 are shown as ovular strips for the purposes of illustration. Inpractice, the access features may have curved or irregular shapes, andthe access features will generally fracture so that they remain attachedto the main portion of the jacket.

The materials and processes used to form the main portion of the jacket12 and the access features 50, 52 can be selected so that the interfacesallow for relatively easy access to the central bore 16 by tearing thejacket 12 as shown in FIG. 2. The cable 10 may be constructed to meetother requirements for robustness, such as requirements for the jacket12 stay intact under tensile loads, twisting, in temperature variations,and when subjected to other known cable test criteria, such as, forexample, ICEA 460, and GR20.

In accordance with aspects of the disclosure, the main portion of thejacket 12 may be extruded from medium density polyethylene (MDPE), andthe access features 50, 52 may be extruded from polypropylene (PP). Thejacket 12 may be formed in a coextrusion process so that the mainportion of the jacket 12 and the access features 50, 52 bond duringcooling to form relatively strong bonds at the interfaces.

As shown in FIGS. 1 and 2, access features 50 and 52 may be positionedwithin cable jacket to be proximate with and radially exterior tooverlap sections 44 and 46, respectively. As shown in FIG. 2, when cablejacket 12 is opened, splits 54 and 56 are formed along the length ofcable jacket 12 generally at the position of access features 50 and 52,respectively. With access features aligned with overlap sections 44 and46, when cable jacket 12 is opened, armor layer 30 may also be opened byseparating armor segment 32 from armor section 34 at the same time orwith the same opening action that opens cable jacket 12. Thus, incertain embodiments, when cable jacket 12 is opened, armor layer 30 isalso opened providing efficient access to the elements of core 26.During manufacture, the two armor segments 32 and 34 traveling into thejacketing extruder will facilitate precise control of the angularposition of the overlaps 44 and 46 with respect to the fast accesscoextruded features 50 and 52.

The overlaps may be formed in a variety of ways. For example, thestrength members may be placed adjacent to the overlap so that there isonly one armor steel thickness between wire and tube, facilitatingsmaller outside diameter cable. The strength member, which may be asteel wire for example, may be spot welded to one segment of armor,while the other strength member may be spot welded to the other segmentof armor. This may provide extra cable strength to oppose unintendedfast access jacket opening, or for twist resistance, or for otherphysical strength features. As shown in FIG. 9, for example, theoverlaps may be formed so that one halves' overlaps are both on theoutside, or both on the inside, or one overlap is on the outside and oneinside. In accordance with yet other aspects of the present disclosure,the armor segment halves may be butted, with no overlap at all (one sideor both). The two armor halves may be symmetrical, or asymmetrical. Theangle of the armors could be symmetrical (both at 180° plus the overlapdistance), or one armor segment could be less than, or significantlyless than 180°, where the smaller armor could act like a ‘lid’ or ‘top’of the container that can be taken off. The strength members may beadjacent, on top of, or up to 90° away from the overlaps.

As shown in FIG. 10, a butt splice 31 of the two armor halves 32, 34 maybe provided with a cover piece 35. The cover piece in turn may act as aripcord for easy access to the core of the cable. In addition, a buttsplice may be formed under the strength members 58 and 59, respectively,or abutting the strength members and formed with a high-strength polymerto bond and reinforce the seam.

In some embodiments, a bonding agent (e.g., Maleic anhydride, ethyleneacrylic acid copolymer, etc.) may be used in or adjoining cable jacket12 to increase bonding between the inner surface of cable jacket 12 andthe outer surface of armor layer 30. The bonding between cable jacket 12and armor layer 30 may facilitate opening of both layers together with asingle opening action. Specifically, as cable jacket 12 is opened, armorlayer 30 may remain bound to cable jacket 12 causing armor segment 32 toseparate from armor segment 34 along overlap sections 44 and 46. Thebonding agent may also act to prevent relative sliding of edges oftwo-piece armor layer 30, and the bonding agent may also be used toprevent relative sliding of the components of any of the otherembodiments disclosed herein.

In one embodiment, the outer surfaces of armor layer 30 may include amaterial or coating (e.g., a thermoplastic exterior coating) that, whenheated, bonds to the thermoplastic of cable jacket 12. In one suchembodiment, the exterior coating of armor layer 30 is melted by the heatof the material of cable jacket 12 as the jacket is extruded over armorlayer 30 and the subsequent cooling bonds together the materials ofcable jacket 12 and the exterior coating of armor layer 30. In anotherembodiment, an induction heater is used to heat armor layer 30, causingthe exterior coating of armor layer 30 to melt and bond to the innersurface of cable jacket 12. In one embodiment, the exterior coating ofarmor layer 30 is an ethylene acrylic acid copolymer (EAAC).

As discussed above, cable 10 includes a binder film 28 located betweenthe elements of core 16 and armor layer 30. In some embodiments, theouter surface of binder film 28 is bonded to the inner surface of armorlayer 30 (e.g., with glue, bonding agent, etc.) so that when cablejacket 12 is opened utilizing access features 50 and 52, binder film 28remains bound to armor layer 30 and armor layer 30 remains bound tocable jacket 12. Thus, a single opening action splitting cable jacket 12along access features 50 and 52 acts to open armor layer 30 and binderfilm 28. In one embodiment, an induction heater is used to heat armorlayer 30 causing the material of film 28 to melt and bond to the innersurface of armor layer 30. In one such embodiment, air may be injectedinto the center of film 28, pushing film 28 outward to engage the innersurface of armor layer 30 during heating to increase bonding betweenfilm 28 and armor layer 30.

Referring back to FIGS. 1 and 2, strength members 58 and 59 may beprovided at diametrically positions embedded in and runninglongitudinally within the jacket 12. Strength members 58 and 59 maydefine a neutral axis of the cable 10 perpendicular to the longitudinalaxis. The strength members 58 and 59 may be steel wires and may beflattened on the jacket line so that the cable jacket thickness may beminimized for material cost reduction. As shown in FIG. 11, the positionof the fast access features 50 and 52 with respect to the strengthmembers 58 and 59 and the overlaps 44 and 46 may be fixed or varied toenable additional features, like fast access feature robustness duringextreme cable mechanical duress. For example, placing the fast accessfeature on the other side of strength member, the jacket wrap around thestrength member may act like a ‘key’ that strengthens or buffers thefast access feature from the zippering action of the twisted cableoverlap. The jacket extending around the strength member may also be anextra notch for efficient opening access by a field technician.

In accordance with aspects of the present disclosure, as shown in FIG.3, the armor segments 32 and 34 may be formed from one piece of steel.If the armor is to be corrugated, the armor piece may be partiallyscored and run through the corrugator. An armor separator device may beprovided after the corrugator, or act of corrugation itself, completesthe armor separation into two pieces. If the armor is going to benon-corrugated, the scored and separated armor travels to two sets (onehalf each) of forming rollers.

In accordance with yet other aspects of the present disclosure, thearmor segments 32 and 34 may be sheared. Chord-shear is a repeatingsheared shape 35 that after the steel is formed into a cylinder and across section is taken, it appears as if a saw has cut partially throughthe cylinder, creating a ‘chord’ on the cross-sectional circle. As shownin FIG. 3, a shear device may regularly shear armor in middle of thearmor width, repeating at a fixed axial distance. If sheared and formedinto a cylinder, during cycle flex, cracks in the armor are allowed tobuckle in compression and stretch apart in tension, but new cracks andcrack propagation does not occur. For example, when core diameterbecomes larger, (15+ mm), non-corrugated armor with chord shear mayprovide the ability to use non-corrugated armor for all cable diameters.

Cycle flex of finished cable will contract and lengthen the opensections; therefore no new armor cracks will form. As the chord-sheararmor is stretched before extrusion, the armor will form expanded metalsections at the sheared sections which will foster melting or stickingof the jacket directly to the thin film binder 28 or directly to the PEtube 20 through the expanded sections. During the fast access processdescribed herein for accessing the core of the cable, the expanded metalsections will provide a feel and sound during stripping. Hot Formedsteel may offer higher elongation-to-break levels that fosters morestretch, up to 60% elongation as compared to regular cold rolled steelarmor at 5% elongation to break.

As shown in FIG. 4, the chord-sheared edges 37 may stand up from thearmor surface 39 or may be formed to stand up. In this manner, thechord-sheared edges 37 may partially embed into the jacket during theextrusion process which, for example, may cause squirrel/rodentirritation before full jacket is removed. In accordance with otheraspects of the present disclosure, shear-edges on one side may bepressed up, with shear-edges on the opposite side pressed down, so thatduring cycle flex, the two edges do not interfere and on the compressiveside of the cable bend, allowing chord-shear armor to work withouthaving to be stretched.

As shown in FIG. 5, round or tear-drop shaped sections 41, for example,may be punched out of the armor, so that the armor does not have to bestretched or expanded to open up the sheared/punched armor sections. Asshown in FIG. 6, the shear shape may include curved edges 43 at ortoward the ends to stop crack propagation.

As shown in FIGS. 7A and 7B, the shear shape 35 may be adjusted to haveround ends to prevent crack propagation, but also be a partial shear tonot remove any material. In essence, tabs 45 may be created that can bepressed toward the core or into the jacket. The embodiment shown inFIGS. 7A and 7B illustrates the tabs helping to lock the core or tube tothe jacket to enable a ‘laminated PE/steel/PE’ structure. Many differentchord-shear patterns may be used with the two-piece armor. For example,there could be three tabs, then one open punched area, then three moretabs—to get both locking and actual sticking together of the jacketmaterial and the binder or tube materials. FIG. 8 is an exampleillustrating a set of staggered shear cuts 47 made in the metal thatexpand when the metal armor is stretched under tension prior to beingformed around the core of the cable.

In general, the separation properties disclosed in this specificationmay be obtained by coextruding the discontinuities from a differentmaterial than the material used to form the primary portion of thejacket. As an alternative method, the discontinuities may be made fromthe same material as the remainder of the jacket, but subjected todifferent curing conditions, for example.

What is claimed is:
 1. A cable, comprising: a core; a first armorcomponent having a first longitudinal edge and a second longitudinaledge; a second armor component having a third longitudinal edge and afourth longitudinal edge, wherein the first armor component and thesecond armor component are formed to surround the core with at least oneof the first longitudinal edge abutting the third longitudinal edgeand/or the second longitudinal edge abutting the fourth a longitudinaledge; and a jacket surrounding the core, the first armor component, andthe second armor component.
 2. The cable of claim 1, further comprisinga cover piece, wherein the cover piece runs longitudinally adjacentwhere the first longitudinal edge abuts the third longitudinal edgeand/or the second longitudinal edge abuts the fourth a longitudinaledge.
 3. The cable of claim 1, wherein the jacket further comprises anaccess feature, the access feature comprising: a primary portion of afirst extruded polymeric material; and at least one discontinuity of asecond extruded polymeric material in the primary portion, thediscontinuity extending along a longitudinal length of the cable,wherein a bond between the discontinuity and the primary portion allowsthe jacket to be separated at the discontinuity.
 4. The cable of claim3, wherein the discontinuity is provided at a predetermined angularposition along a circumference of the jacket to provide precisealignment of the access feature with at least one of the longitudinaledges.
 5. The cable of claim 1, further comprising a plurality ofstrength members, at least two of the strength members defining aneutral axis of the cable perpendicular to a longitudinal axis of thecable..
 6. The cable of claim 5, wherein the strength members arediametrically opposed.
 7. The cable of claim 1, wherein an arc length ofthe first armor component is greater than an arc length of the secondarmor component when the cable is viewed in cross-section.
 8. The cableof claim 1, wherein the first armor component and the second armorcomponent define a core diameter.
 9. The cable of claim 8, wherein thefirst armor component and the second armor component are non-corrugatedand the core diameter is 10 mm or less.
 10. The cable of claim 9,wherein the first armor component and the second armor component have aflat thickness of approximately 0.17 mm.
 11. The cable of claim 1,further comprising a buffer tube having an outer buffer tube diameter,wherein the outer buffer tube diameter is substantially equal to thecore diameter such that a gap between the buffer tube and the firstarmor component and the second armor component is minimized.
 12. Thecable of claim 1, wherein the core comprises a polyethylene binder filmsurrounding a plurality of core elements.
 13. The cable of claim 12,wherein the core elements include at least one buffer tube surrounding aplurality of optical fibers.
 14. The cable of claim 13, wherein theplurality of optical fibers comprises 200 micrometer low loss opticalfibers.
 15. The cable of claim 9, wherein the first armor component andthe second armor component comprise a neutral axis, and wherein theneutral axis of each of the first armor component and the second armorcomponent are situated radially away from a center of the cable duringbending.